In the last few years, methanol dissociation has been devoted a growing attention. The synthesis gas, composed of about 33 vol.% CO and 66 vol.% H.sub.2, can be obtained according to equation (1). EQU CH.sub.3 OH.revreaction.CO+2H.sub.2 ( 1)
Reaction (1) is highly endothermic and can be carried out at temperatures over 200.degree. C. under atmospheric or lower methanol pressure with the help of certain heterogeneous catalysts. Thus, Inui, et al, J. Japan Petrol., Inst. 25, 121 (1982), investigated the effect of Ni--, Rh--, or Ru-- on SiO.sub.2 -- catalyst in comparison to the commercial ZnO--Cr.sub.2 O.sub.3 -- methanol synthesis catalysts. The best results were obtained with Ni--Ru-on-La.sub.2 O.sub.3 or on-SiO.sub.2. This catalyst was far superior to the commercial ZnO--Cr.sub.2 O.sub.3 -- catalyst. However, with an increase of methanol conversion (over 30%), coke was laid down on the catalyst according to equations (2) and (3). EQU 2CH.sub.3 OH.fwdarw.C+CO.sub.2 +4H.sub.2 ( 2) EQU CH.sub.3 OH.fwdarw.C+H.sub.2 +H.sub.2 O (3)
Another industrially interesting reaction is the methanol steam reforming reaction, which follows equation (4) and leads to a gas mixture of 25 vol.% CO.sub.2 and 75 vol.% H.sub.2. EQU CH.sub.3 OH+H.sub.2 .revreaction.CO.sub.2 +3H.sub.2 ( 4)
This endothermic reaction can be considered as a combination of methanol dissociation (1) and CO-water gas shift according to equation 5. EQU CO+H.sub.2 O.fwdarw.CO.sub.2 +H.sub.2 ( 5)